Patients with primary biliary cirrhosis suffer from severe bouts of itching, which is manifested by chronic scratching. In order to evaluate the efficacy of experimental drugs that may relieve the itching, it is necessary to quantify the scratching. A piezoelectric foil cemented to an orthotic attached to the patient's primary scratching finger transduced mechanical vibrations, generated by the scratching, into an electrical signal applied to the input of a miniature FM transmitter. After the signal was obtained with an FM receiver, it was processed by a custom-designed frequency counter, which in turn was interrogated and reset periodically by a personal computer. The experiment consisted of a double blind controlled study of four consecutive 24H infusions of Naloxone or placebo. An additional controlled study was performed using the orally equivalent drug Nalmafene to study its efficacy in the amelioration of the pruritus associated with cholestatic liver disease. This is a continuation of Intramural Research Project Z01-RR-10303-08 BEI.